Consolidate import_helper functions.

Author: jaraco

importlib_resources/tests/util.py

@@ -9,30 +9,7 @@
 from . import zipdata01
 from .._compat import ABC, Path, PurePath, FileNotFoundError
 from ..abc import ResourceReader
-
-try:
-    from test.support import modules_setup, modules_cleanup
-except ImportError:
-    # Python 2.7.
-    def modules_setup():
-        return sys.modules.copy(),
-
-    def modules_cleanup(oldmodules):
-        # Encoders/decoders are registered permanently within the internal
-        # codec cache. If we destroy the corresponding modules their
-        # globals will be set to None which will trip up the cached functions.
-        encodings = [(k, v) for k, v in sys.modules.items()
-                     if k.startswith('encodings.')]
-        sys.modules.clear()
-        sys.modules.update(encodings)
-        # XXX: This kind of problem can affect more than just encodings. In
-        # particular extension modules (such as _ssl) don't cope with reloading
-        # properly.  Really, test modules should be cleaning out the test
-        # specific modules they know they added (ala test_runpy) rather than
-        # relying on this function (as test_importhooks and test_pkg do
-        # currently).  Implicitly imported *real* modules should be left alone
-        # (see issue 10556).
-        sys.modules.update(oldmodules)
+from ._compat import import_helper
 
 
 try:
@@ -205,8 +182,8 @@ def tearDownClass(cls):
             pass
 
     def setUp(self):
-        modules = modules_setup()
-        self.addCleanup(modules_cleanup, *modules)
+        modules = import_helper.modules_setup()
+        self.addCleanup(import_helper.modules_cleanup, *modules)
 
 
 class ZipSetup(ZipSetupBase):